Industry has been looking for ways to clean hydraulic tubing that can replace the current method of vapor degreasing. A vapor degreaser is a large organic solvent still on which the solvent vapor condenses and drains off the parts to be cleaned. Vapor degreaser systems are large, fixed installations that have a high purchase price and maintenance costs. Companies that use this method also must obtain a yearly operating permit for their facilities from the Clean Air Agencies because of the potential for air pollution and health risks that this cleaning method poses. Replacing these vapor degreasers with small, low-cost cleaning methods allows installations to consolidate sites and save money.
The pellet system is currently used to clean tubes at a relatively high rate in close quartered work cells. Tubes are bent into a large variety of complicated shapes and lengths. Pellets must be loaded, launched/retrieved and examined with a minimum of operator movement. Equipment that requires the operator to find and retrieve the spent pellet lowers productivity. Safety and noise consideration require that the pellets be fired into a containment device and that the noise be reduced to acceptable levels.
One method is to propel a polyurethane foam pellet through the tube using compressed air. The tight fitting foam pellet scrubs the interior wall of the tube as it passes through. This is a widely used technique and there are at least three makers of pellets and pellet launching equipment worldwide. One component lacking from the vendors is equipment to capture and return the spent pellet to the operator so that it may be examined.